Large industrial machines such as those used in material transportation can be very heavy, especially when fully loaded. For this reason, a parking brake or emergency brake (both referred to interchangeably herein as a “parking brake”) is often needed to ensure that the machine comes to a complete stop when commanded, and to ensure that once stopped, the machine does not undergo unwanted movement, such as by rolling down a grade under the influence of gravity. The latter is referred to as the machine's “slope-holding” capability.
One such heavy industrial machine that requires enhanced slope-holding capabilities is the articulated truck. This type of truck is often used for heavy material hauling and is typically employed in treacherous off-road conditions. The weight of the machine when loaded may be twice that of the empty machine. As such, the required slope-holding capability of the machine when fully loaded may be substantial.
Additional brakes may be used. For example, a parking lock device for a machine is shown in U.S. Pat. Pub. US2009/0050435. The parking lock device is mounted on a transmission of the machine. However, it will be appreciated from the following description that enhanced control measures are needed if an extra brake is to provide enhanced slope-holding capability while also providing long component life and high spatial efficiency.
The present disclosure is directed to a system and method to improve machine emergency braking in order to address one or more of the problems or shortcomings set forth above. However, it should be appreciated that the solution of any particular problem is not a limitation on the scope of this disclosure or of the attached claims except to the extent expressly noted. Additionally, this background section discusses problems and solutions noted by the inventors; the inclusion of any problem or solution in this section is not an indication that the problem or solution represents known prior art except as otherwise expressly noted.